Rotary compressors, each of which includes a hush supporting a piston eccentrically rotating within the cylinder chamber of a cylinder, have been conventionally known. Some of the rotary compressors include, as described in Japanese Unexamined Patent Publication No. H8-42474, a bush provided with an oil supply passage and an oil reservoir.
The rotary compressor of Japanese Unexamined Patent Publication No. H8-12474 is a rolling piston compressor. In this rotary compressor, a cylinder has a circular groove in which a bush is fitted in, and a blade supported by the bush to be movable back and forth and integrally formed with a piston. This blade segments a cylinder chamber of the cylinder into a high-pressure chamber and a low-pressure chamber.
The bush includes a pair of substantially semicylindrical members. One of the members is located at the high-pressure chamber of the cylinder chamber. The other member is located at the low-pressure chamber of the cylinder chamber. A flat side surface of each bush member slides back and forth along the outer surface of the blade. A curved side surface of each bush member slides to swing along the inner surface of the circular groove of the cylinder.
The above-described oil supply passage of the bush laterally penetrates the bush. The above-described oil reservoir of the bush is formed at each of the flat side surface and the curved side surface. One end of the oil supply passage of the bush open to the oil reservoir at the flat side surface (i.e., the blade-side oil reservoir). The other end is open to the oil reservoir at the curved side surface (i.e., the groove-side oil reservoir). Lubricant is supplied from an oil passage inside the blade to the oil reservoir at the flat side surface of the bush. The lubricant is supplied to the sliding surface of the bush along the blade. The lubricant, which has been supplied to the oil reservoir at the flat side surface of the bush, is supplied through the oil supply passage of the bush to the oil reservoir at the curved side surface of the bush.